New Telescope to Take First-Ever Black Hole Photo

Below:

Next story in Space

A group of astronomers are meeting this week to plan out an
ambitious and unprecedented project — capturing the first-ever
image of a black hole.

The researchers want to create an Earth-size virtual instrument
called the Event Horizon Telescope, a worldwide network of radio
telescopes powerful enough to snap a picture of the supermassive
black hole at the heart of our Milky Way galaxy.

"Nobody has ever taken a picture of a
black hole," Dimitrios Psaltis, of the University of
Arizona's Steward Observatory, said in a statement. Psaltis is a
co-organizer of the conference, which began today (Jan. 18) in
Tucson, Ariz. "We are going to do just that."

An elusive target

Black holes are exotic structures whose gravitational fields are
so powerful that they trap everything, even light. They were
first postulated by Albert Einstein's
theory of general relativity.

Astronomers have detected plenty of black holes in our galaxy and
beyond via indirect means. It's thought that most, if not all,
galaxies harbor a supermassive black hole at their cores.
[ Gallery:
Black Holes of the Universe ]

However, scientists have yet to image a black hole. Researchers
working on the Event Horizon Telescope — named after a black
hole's "point of no return," beyond which nothing can escape —
hope to change that.

"Even five years ago, such a proposal would not have seemed
credible," said Sheperd Doeleman of MIT, the project's principal
investigator. "Now we have the technological means to take a stab
at it."

Doeleman and his team want to create a network of up to 50
radio telescopes around the world, which will work in concert
to get the job done.

"In essence, we are making a virtual telescope with a mirror that
is as big as the Earth," Doeleman said. "Each radio telescope we
use can be thought of as a small silvered portion of a large
mirror. With enough such silvered spots, one can start to make an
image."

Imaging a black hole's 'shadow'

The team plans to point the Event Horizon Telescope at the
supermassive black hole at the Milky Way's center, which is about
26,000 light-years away and is thought to hold as much mass as 4
million suns.

That's pretty big, but picking the object out at such a great
distance is equivalent to spotting a grapefruit on the surface of
the moon, researchers said.

"To see something that small and that far away, you need a
very big telescope, and the biggest telescope you can make on
Earth is to turn the whole planet into a telescope," said Dan
Marrone of the Steward Observatory.

Researchers hope to get a picture of the black hole's outline, or
"shadow."

"As dust and gas swirls around the black hole before it is drawn
inside, a kind of cosmic traffic jam ensues," Doeleman said.
"Swirling around the black hole like water circling the drain in
a bathtub, the matter compresses and the resulting friction turns
it into plasma heated to a billion degrees or more, causing it to
'glow' — and radiate energy that we can detect here on Earth."

General relativity predicts that the black hole’s shadow should
be a perfect circle. So the Event Horizon Telescope's
observations could provide a test of Einstein's venerable theory,
researchers said.

"If we find the black hole’s shadow to be oblate instead of
circular, it means Einstein’s theory of general relativity must
be flawed," Psaltis said. "But even if we find no deviation from
general relativity, all these processes will help us understand
the fundamental aspects of the theory much better."

The team hopes to keep adding more instruments to the telescope
over time, providing a sharper image of our galaxy's central
black hole as the months and years go by.